1 files changed, 12 insertions, 16 deletions
diff --git a/src/init.cpp b/src/init.cpp
index 7215e87359..d1d733af94 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1143,23 +1143,10 @@ bool AppInitParameterInteraction()
 
 static bool LockDataDirectory(bool probeOnly)
 {
-    std::string strDataDir = GetDataDir().string();
-
     // Make sure only a single Bitcoin process is using the data directory.
-    fs::path pathLockFile = GetDataDir() / ".lock";
-    FILE* file = fsbridge::fopen(pathLockFile, "a"); // empty lock file; created if it doesn't exist.
-    if (file) fclose(file);
-
-    try {
-        static boost::interprocess::file_lock lock(pathLockFile.string().c_str());
-        if (!lock.try_lock()) {
-            return InitError(strprintf(_("Cannot obtain a lock on data directory %s. %s is probably already running."), strDataDir, _(PACKAGE_NAME)));
-        }
-        if (probeOnly) {
-            lock.unlock();
-        }
-    } catch(const boost::interprocess::interprocess_exception& e) {
-        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. %s is probably already running.") + " %s.", strDataDir, _(PACKAGE_NAME), e.what()));
+    fs::path datadir = GetDataDir();
+    if (!LockDirectory(datadir, ".lock", probeOnly)) {
+        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. %s is probably already running."), datadir.string(), _(PACKAGE_NAME)));
     }
     return true;
 }
@@ -1223,6 +1210,15 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
     LogPrintf("Using config file %s\n", GetConfigFile(gArgs.GetArg("-conf", BITCOIN_CONF_FILENAME)).string());
     LogPrintf("Using at most %i automatic connections (%i file descriptors available)\n", nMaxConnections, nFD);
 
+    // Warn about relative -datadir path.
+    if (gArgs.IsArgSet("-datadir") && !fs::path(gArgs.GetArg("-datadir", "")).is_absolute()) {
+        LogPrintf("Warning: relative datadir option '%s' specified, which will be interpreted relative to the "
+                  "current working directory '%s'. This is fragile, because if bitcoin is started in the future "
+                  "from a different location, it will be unable to locate the current data files. There could "
+                  "also be data loss if bitcoin is started while in a temporary directory.\n",
+            gArgs.GetArg("-datadir", ""), fs::current_path().string());
+    }
+
     InitSignatureCache();
     InitScriptExecutionCache();